Replaceable conductive marker tip

Abstract

Embodiments of the invention provide a removable marker tip configured for application with an active pen-stylus. The removable marker tip comprises an antenna and an insulator and is designed to be held onto the pen-stylus' writing shaft by a set of crush ribs fitted into a posterior recess on the removable marker tip. The removable marker tip is designed to be a consumable part to improve the paper feeling received by users of the pen-stylus as they draw on the display of a tablet device. The removable marker tip is further designed to be hand-removable by users of the pen-stylus.

The invention claimed is: 
     
       1. An active pen-stylus, comprising:
 a removable marker tip having a first antenna and an insulator; 
 a writing shaft adapted to receive and hold the removable marker tip; 
 a force sensor that receives physical forces imparted to the writing shaft by the removable marker tip when the removable marker tip engages with a display on a tablet device and translates the physical force received into an electronic signal, wherein the electronic signal is transmitted back to the tablet device; and 
 a second antenna, wherein the second antenna surrounds the first antenna but has a horizontal placement in the active pen-style that avoids overlap with the first antenna, 
 wherein signals received by the tablet device from the first antenna and the second antenna enable the tablet device to calculate an orientation of the active pen-stylus with respect to the display of the tablet device. 
 
     
     
       2. The active pen-stylus of  claim 1  wherein the first antenna comprises a transmitter and the second antenna comprises a transceiver that receives signals from tablet device. 
     
     
       3. The active pen-stylus of  claim 1  wherein the removable marker tip further comprises a posterior opening having crush ribs that fit onto the writing shaft and secure the removable marker tip to the writing shaft. 
     
     
       4. The active pen-stylus of  claim 3  wherein the crush ribs are aligned to avoid delivering rotational forces to the writing shaft. 
     
     
       5. The active pen-stylus of  claim 1  wherein the first antenna of the removable marker tip comprises a first consumable material and the insulator comprises a second consumable material wherein the first consumable material and the second consumable material emulate for users of the active pen-stylus sensations similar to applying one of a pen and pencil to paper when using the active pen-stylus to draw on the display of the tablet device. 
     
     
       6. The active pen-stylus of  claim 5  wherein the first consumable material of the first antenna comprises a conductive carbon fiber material. 
     
     
       7. The active pen-stylus of  claim 5  wherein the first consumable material of the first antenna comprises a polymeric binder filled with at least one of a carbon fiber, carbon nanotubes (CNT), carbon black powder, carbon nanofibers (CNF), graphite, conductive mica, conductive mica (powder), carbon fiber (chopped, milled), multi-wall carbon nanotubes (MWCNT), and graphene nanotubes (GNT). 
     
     
       8. The active pen-stylus of  claim 5  wherein the second consumable material of the insulator comprises a glass-filled nylon. 
     
     
       9. The active pen-stylus of  claim 1  wherein the removable marker tip is hand-removable from the writing shaft. 
     
     
       10. The active pen-stylus of  claim 1  wherein the first antenna is overmolded with the insulator.